From 87ab487d59fa85dbe2afa55cc841b02805ae42ca Mon Sep 17 00:00:00 2001
From: Louis Burda <quent.burda@gmail.com>
Date: Fri, 7 Apr 2023 17:18:18 -0400
Subject: Reorder days into src

---
 src/13/solve.py | 148 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 148 insertions(+)
 create mode 100644 src/13/solve.py

(limited to 'src/13/solve.py')

diff --git a/src/13/solve.py b/src/13/solve.py
new file mode 100644
index 0000000..e89466c
--- /dev/null
+++ b/src/13/solve.py
@@ -0,0 +1,148 @@
+import sys
+sys.path.append("../common")
+import aoc
+
+tmap = [list(l) for l in aoc.data.split("\n") if len(l) != 0]
+xlen, ylen = len(tmap[0]), len(tmap)
+
+arrows = dict()
+arrows["<"] = (-1, 0)
+arrows[">"] = (1, 0)
+arrows["^"] = (0, -1)
+arrows["v"] = (0, 1)
+
+directions = [(-1,0), (0,-1), (1, 0), (0, 1)] # l - u - r - d
+
+def check_pos(x, y):
+    if x < xlen and x >= 0 and y < ylen and y >= 0:
+        return tmap[y][x]
+    return " "
+
+def correct(x, y):
+    cr = check_pos(x+1, y)
+    cl = check_pos(x-1, y)
+    cu = check_pos(x, y-1)
+    cd = check_pos(x, y+1)
+
+    if cr == "|": cr = " "
+    if cl == "|": cl = " "
+    if cu == "-": cu = " "
+    if cd == "-": cd = " "
+
+    r = cr != " "
+    l = cl != " "
+    u = cu != " "
+    d = cd != " "
+
+    vsum = r + l + u + d
+    if vsum > 2:
+        return "+"
+
+    # 2 around
+    if r:
+        if l:
+            return "-"
+        elif u:
+            return "/"
+        else:
+            return "\\"
+    else:
+        if not l:
+            return "|"
+        elif u:
+            return "/"
+        else:
+            return "\\"
+
+carts = list()
+for y in range(ylen):
+    for x in range(xlen):
+        if tmap[y][x] in arrows:
+            carts.append([x, y, arrows[tmap[y][x]], 0, 0])
+            tmap[y][x] = correct(x,y)
+
+def cart_at(x, y):
+    global carts
+    for i in range(len(carts)):
+        c = carts[i]
+        if c[0] == x and c[1] == y and not c[4]:
+            return i
+    return None
+
+def draw_map():
+    for y in range(ylen):
+        f = lambda x : "".join(["#" if cart_at(x,y) != None else tmap[y][x]])
+        aoc.debug([f(x) for x in range(len(tmap[y]))])
+
+def advance(cart):
+    ncart = [0 for x in range(5)]
+    ncart[0] = cart[0]+cart[2][0]
+    ncart[1] = cart[1]+cart[2][1]
+    col = cart_at(ncart[0], ncart[1])
+    if col != None:
+        return ncart[0], ncart[1], col
+
+    c = tmap[ncart[1]][ncart[0]]
+    d = directions.index(cart[2])
+
+    if c == "+":
+        d = (d + len(directions)-1 + cart[3]) % len(directions)
+        ncart[2] = directions[d]
+        ncart[3] = (cart[3] + 1) % 3
+    else: # dont need to change direction for '-' and '|'
+        if c == "/":
+            ncart[2] = directions[3-d]
+        elif c == "\\":
+            if d == 0: #l
+                ncart[2] = directions[1]
+            elif d == 1: #u
+                ncart[2] = directions[0]
+            elif d == 2: #r
+                ncart[2] = directions[3]
+            elif d == 3: #d
+                ncart[2] = directions[2]
+        else:
+            ncart[2] = cart[2]
+        ncart[3] = cart[3]
+    return ncart
+
+
+def solve1(args):
+    global carts
+
+    crash = None
+    while not crash:
+        carts = sorted(carts, key=lambda x:(x[0], x[1]))
+        for c in range(len(carts)):
+            nc = advance(carts[c])
+            if len(nc) == 3:
+                crash = nc
+                break
+            else:
+                carts[c] = nc
+
+    return f"{crash[0]},{crash[1]}"
+
+def solve2(args):
+    global carts
+
+    while len(carts) > 1:
+        carts = sorted(carts, key=lambda x:(x[0], x[1]))
+        rcarts = list()
+        for c in range(len(carts)):
+            if carts[c][4]: continue;
+            nc = advance(carts[c])
+            if len(nc) == 3:
+                carts[c][4] = 1
+                carts[nc[2]][4] = 1
+                rcarts.append(carts[c])
+                rcarts.append(carts[nc[2]])
+            else:
+                carts[c] = nc
+        for c in rcarts:
+            if c in carts: # prevent doubles
+                carts.remove(c)
+
+    return f"{carts[0][0]},{carts[0][1]}"
+
+aoc.run(solve1, solve2)
-- 
cgit v1.2.3-71-gd317